1. Technical Field
The present invention relates generally to digital image printing; and, more particularly, it relates to probability error diffusion techniques applied to digital image printing systems.
2. Description of Prior Art
Conventional digital image printing systems commonly employ various methods of error diffusion to pixel intensity. Classic error diffusion generates a pseudo random pixel structure having intermediate levels of the pixel intensities. The intermediate level of a given pixel is adapted to the nearest intensity that can be generated using the available resources of the printing system. The difference between the actual pixel information and the nearest intensity that is chosen to print the pixel is recorded and this difference is an error to which the error diffusion method is applied. The error is spread or diffused over pixels adjacent to the pixel used in a predetermined mask.
Drawbacks of the classical error diffusion method when applied to the pixel's intensity include the fact that pixel intensity, when viewed within a certain spatial vicinity, are inherently coupled one to another. For example, the human eye integrates a group of the image data as a function of the intensity of the pixels in a near spatial vicinity to the pixel. The fact that the classic error diffusion method uses the pixel characteristic of intensity results in many deleterious visible effects and performance limitations. The pixel characteristic of intensity is intrinsically coupled to the pixels in the near vicinity of the pixel. The performance limitation of the classic error diffusion method stems primarily from the fact that is impossible to decouple the intensity characteristic of the pixel absent some additional image processing.
Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art after reviewing the remainder of the present application with reference to the drawings.